Integrated magnetic elements

ABSTRACT

An integrated magnetic element is provided, including a first magnetic-core frame, three second magnetic-core frames, and three coil windings. The first magnetic-core frame has a first side pillar and a second side pillar opposite to the first side pillar. The three second magnetic-core frames are arranged on the side corresponding to the first side pillar of the first magnetic-core frame, and are arranged in parallel with the axis of the first side pillar of the first magnetic-core frame. Each of the second magnetic-core frames has a first side pillar adjacent to the first side pillar of the first magnetic-core frame, and a second side pillar opposite to the first side pillar of itself. The three coil windings connect to a three-phase grid, and wind around the first side pillar of the first magnetic-core frame and the corresponding first side pillar of the second magnetic-core frame respectively.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority of China Patent Application No.201710963855.8, filed on Oct. 17, 2017, the entirety of which isincorporated by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The application relates in general to an integrated magnetic element,and in particular to an integrated magnetic element having common-modeeffect and different-mode effects at the same time.

Description of the Related Art

In recent years, power supply units and power converters have beenwidely used. However, when the power supply unit or the power converteris operating, a phenomenon known as electromagnetic interference (EMI)may occur due to high-frequency switching, which can affect theoperation of electronic device. A common practice employed forpreventing noise from entering electronic devices is to adapt a filtercircuit. However, the filter circuits that are commonly used toeliminate noise have some obvious defects. For example, the magneticcore of the filter circuit is usually made of a silicon steel sheet, butthe high-frequency characteristics of the silicon steel sheet are poor,and when the inductor is made of a silicon steel sheet, it has worseeffect at high frequency, which means that the filtering efficiency mustbe enhanced with additional components. For example, in a high-levelanti-EMI requirement, a pair of grounding capacitors may need to beadded to the P, N input terminals in the structure of the two-phasereactor, but these capacitors may increase the leakage current and alsoincrease the size and complexity of the device. Therefore, how toprovide a magnetic element with both better common-mode anddifferential-mode filtering effects at the same time is a problem thatneeds to be solved immediately.

BRIEF SUMMARY OF INVENTION

An embodiment of the present invention provides an integrated magneticelement, including a first magnetic-core frame, three secondmagnetic-core frames, and three coil windings. The first magnetic-coreframe has a first side pillar and a second side pillar opposite to thefirst side pillar. Three second magnetic-core frames are arranged on aside corresponding to the first side pillar of the first magnetic-coreframe, and are arranged in parallel with the axis of the first sidepillar of the first magnetic-core frame. Each of the secondmagnetic-core frames has a first side pillar adjacent to the first sidepillar of the first magnetic-core frame, and a second side pillaropposite to the first side pillar of itself. Three coil windings areconnected to a three-phase grid, and wind around the first side pillarof the first magnetic-core frame and the corresponding first side pillarof the second magnetic-core frame respectively.

Another embodiment of the present invention provides an integratedmagnetic element, including a first magnetic-core frame, three secondmagnetic-core frames, a third magnetic-core frame, three first coilwindings, and three second coil winding. The first magnetic-core framehas a first side pillar and a second side pillar opposite to the firstside pillar. Three second magnetic cores are arranged on a side of thefirst side pillar of the first magnetic-core frame, and are arranged inparallel with the axis of the first side pillar of the firstmagnetic-core frame. Each of the second magnetic-core frames has a firstside pillar adjacent to the first side pillar of the first magnetic-coreframe, and a second side pillar opposite to the first side pillar ofitself. The third magnetic-core frame is arranged on a side of thesecond side pillar of the three second magnetic-core frames, and has afirst side pillar adjacent to the second side pillar of the three secondmagnetic-core frames and a second side pillar opposite to the first sidepillar of itself. Three first coil windings are connected to athree-phase grid, and respectively winds around the first side pillar ofthe first magnetic-core frame and the corresponding first side pillar ofthe second magnetic-core frame. Three second coil windings respectivelywinds around the corresponding second side pillar of the secondmagnetic-core frame and the first side pillar of the third magnetic-coreframe.

Another embodiment of the present invention provides an integratedmagnetic element, including a magnetic-core frame, three C-type magneticcores and three coil windings. The magnetic-core frame has a first sidepillar and a second side pillar opposite to the first side pillar. ThreeC-type magnetic cores are arranged on a side corresponding to the firstside pillar of the magnetic-core frame, and are arranged in parallelwith the axis of the first side pillar of the magnetic-core frame. Eachof the C-type magnetic cores has a side pillar adjacent to the firstside pillar of the magnetic-core frame. The three coil windings areconnected to the output terminal of a VFD (Variable-frequency Drive)system, and respectively winds around the first side pillar of themagnetic-core frame and the corresponding side pillar of the C-typemagnetic core. Each of the C-type magnetic cores has a gap, located on aside opposite to the side pillar of itself, and each of the gaps has aHall sensor disposed therein.

Another embodiment of the present invention provides an integratedmagnetic element, including a magnetic-core frame, a first C-typemagnetic core, a second C-type magnetic core, a first coil winding, anda second coil winding. The magnetic-core frame has a first side pillarand a second side pillar opposite to the first side pillar. The firstC-type magnetic core is arranged on a side of the first side pillar ofthe magnetic-core frame, and has a side pillar adjacent to the firstside pillar of the magnetic-core frame. The second C-type magnetic coreis arranged on a side of the second side pillar of the magnetic-coreframe, and has a side pillar adjacent to the second side pillar of themagnetic-core frame. The first coil winding winds around the first sidepillar of the magnetic-core frame and the side pillar of the firstC-type magnetic core. The second coil winding winds around the secondside pillar of the magnetic-core frame and the side pillar of the secondC-type magnetic core. The first C-type magnetic core has a gap locatedopposite to the side pillar of itself, and the second C-type magneticcore has a gap located opposite to the side pillar of itself. The firstcoil winding and the second coil winding have the same windingdirection.

Another embodiment of the present invention provides an integratedmagnetic element, including a core frame, a core module, a first coilwinding, and a second coil winding. The magnetic-core frame has a firstside pillar and a second side pillar opposite to the first side pillar.The core module includes an E-type magnetic core and an I-type magneticcore. The E-type magnetic core has a center pillar, a first side pillar,a second side pillar and a third side pillar. The third side pillar isperpendicular to the center pillar, the first side pillar and the secondside pillar of the E-type magnetic core. The I-type magnetic core isparallel to the third side pillar of the E-type magnetic core, and isarranged on the side corresponding to the third side pillar of theE-type magnetic core. A gap between the I-type magnetic core and thefirst side pillar of the E-type magnetic core and a gap between theI-type magnetic core and the second side pillar of the E-type magneticcore have the same size. The first coil winding winds around the firstside pillar of the magnetic-core frame and the first side pillar of theE-type magnetic core. The second coil winding winds around the secondside pillar of the magnetic-core frame and the second side pillar of theE-type magnetic core. The core module and the magnetic-core frame arestacked together.

BRIEF DESCRIPTION OF DRAWINGS

The invention can be more fully understood by reading the subsequentdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 is a schematic side view of a three-phase integrated reactor inaccordance with a first embodiment of the present invention.

FIG. 2 is a schematic diagram of the structure of a general convertersystem.

FIG. 3 is a schematic side view of a three-phase integrated reactor inaccordance with a second embodiment of the present invention.

FIG. 4 is a schematic diagram of a circuit architecture having an LCLcircuit.

FIGS. 5A and 5B are schematic side views of an integrated three-phasecurrent sensor common-mode choke with different air gaps in accordancewith a third embodiment of the present invention.

FIGS. 6A and 6B are schematic side views of a two-phase integratedreactor having different air gaps in accordance with a fourth embodimentof the present invention.

FIG. 7 is a schematic diagram of the structure of a general VFD system.

FIG. 8 is a schematic side view of a two-phase integrated reactor havinga ground fault detection function in accordance with a fifth embodimentof the present invention.

FIG. 9A is a schematic side view of an enhanced differential-mode andcommon-mode reactor in accordance with a sixth embodiment of the presentinvention.

FIG. 9B is a schematic side view of a magnetic-core frame of theenhanced differential-mode and common-mode reactor in accordance withthe sixth embodiment of the present invention.

FIG. 9C is a schematic side view of a core module of the enhanceddifferential-mode and common-mode reactor in accordance with the sixthembodiment of the present invention.

DETAILED DESCRIPTION OF INVENTION

Further areas to which the present integrated magnetic element can beapplied will become apparent from the detailed description providedherein. It should be understood that the detailed description andspecific examples, while indicating exemplary embodiments of theintegrated magnetic element, are intended for the purposes ofillustration only and are not intended to limit the scope of theinvention.

FIG. 1 is a schematic side view of a three-phase integrated reactor inaccordance with a first embodiment of the present invention. Thethree-phase integrated reactor includes a first magnetic-core frame 110,three second magnetic-core frames 120 a-120 c, and three coil windingsLa1-La3. The first magnetic-core frame 110 provides the common-modeeffect, and the second magnetic-core frames 120 a-120 c provide thedifferential-mode effect (respectively numbered as CM and DM with arrowindex). Each of the first magnetic-core frame 110 and the secondmagnetic-core frames 120 a-120 c may have a close-looped magneticcircuit with any suitable shape, and each includes a window (such as thewindow 101, 102, 103, 104 shown in FIG. 1). It should be noted thatalthough each of the first magnetic-core frame 110 and the secondmagnetic-core frames 120 a-120 c shown in FIG. 1 is having a rectangularshape, this is only an example of the present invention and it is notlimited thereto. In addition, the windows 101-104 penetrates through thefirst magnetic-core frame 110 and the second magnetic-core frames 120a-120 c from the side shown in FIG. 1 to the opposite side,respectively, so that the coil windings La1-La3 can wind around themagnetic-core frames 110, 120 a-120 c through the windows 101-104,respectively.

In this embodiment, the first magnetic-core frame 110 is formed of afirst side pillar 111 and a second side pillar 112 opposite to eachother, and a third side pillar 113 and a fourth side pillar 114 oppositeto each other. The second magnetic-core frames 120 a-120 c arerespectively composed of corresponding first side pillars 121 a-121 cand second side pillars 122 a-122 c opposite each other, and third sidepillars 123 a-123 c and fourth side pillars 124 a-124 c opposite eachother. The second magnetic-core frames 120 a-120 c are all provided on aside of the first side pillar 111 of the first magnetic-core frame 110,and arranged in parallel with the axis of the first side pillar 111 ofthe first magnetic-core frame 110, which makes the first side pillars121 a-121 c of the second magnetic-core frames 120 a-120 c are adjacentto the first side pillar 111 of the first magnetic-core frame 110,respectively. In addition, the first magnetic-core frame 110 and each ofthe second magnetic-core frames 120 a-120 c are all spaced apart fromeach other by a distance S to form an air gap. In the presentembodiment, the distance S of each space is the same, but this is onlyan example of the present invention, and it is not limited thereto.

The coil windings La1-La3 wind around the first side pillars 111 of thefirst magnetic-core frame 110 and the corresponding first side pillars121 a-121 c of the second magnetic-core frames 120 a-120 c,respectively. For example, as shown in the figure, the coil winding La1winds around the first side pillar 111 of the first magnetic-core frame110 and the first side pillar 121 a of the second magnetic-core frame120 a through the window 101 and the window 102. The coil winding La2winds around the first side pillar 111 of the first magnetic-core frame110 and the first side pillar 121 b of the second magnetic-core frame120 b through the window 101 and the window 103. The coil winding La3winds around the first side pillar 111 of the first magnetic-core frame110 and the first side pillar 121 c of the second magnetic-core frame120 c through the window 101 and the window 104. The winding directionsof the coil windings La1-La3 are the same.

In this embodiment, the first magnetic-core frame 110 and the secondmagnetic-core frames 120 a-120 c can be made of the same material. Forexample, the first magnetic-core frame 110 and the second magnetic-coreframes 120 a-120 c can be made of a silicon steel sheet or iron powdercore. In another embodiment, in order to provide better high-frequencycharacteristics, the first magnetic-core frame 110 which having acommon-mode effect can be made of manganese zinc (MnZn) or ferrite toenhance the suppression of EMI at high frequencies, and each of thesecond magnetic-core frames 120 a-120 c is made of a silicon steel sheetor iron powder core to lower the cost of production.

FIG. 2 is a schematic diagram of the structure of a general convertersystem. The three-phase integrated reactor shown in FIG. 1 can beconnected in series between a three-phase grid 201 and an inverter 202(at the portion “A” shown in left part) which is shown in left part ofFIG. 2 to filter the common-mode noise and the differential-mode noisegenerated by the three-phase grid 201.

FIG. 3 is a schematic side view of a three-phase integrated reactor inaccordance with a second embodiment of the present invention. Thethree-phase integrated reactor includes a first magnetic-core frame 310,three second magnetic-core frames 320 a-320 c, a third magnetic-coreframe 330, three first coil windings La1-La3, and three second coilwindings Lb1-Lb3. The first magnetic-core frame 310 and the thirdmagnetic-core frame 330 are used to provide the common-mode effect whilethe second magnetic-core frames 320 a-320 c are used to provide thedifferential-mode effect (respectively numbered as CM and DM with arrowindex). Each of the first magnetic-core frame 310, the secondmagnetic-core frames 320 a-320 c, and the third magnetic-core frame 330has a close-looped magnetic circuit with any suitable shape, and eachincludes a window, respectively (windows 301, 302, 303, 304, and 305shown in the figure). It should be noted that although each of the firstmagnetic-core frame 310, the second magnetic-core frames 320 a-320 c,and the third magnetic-core frame 330 is having a rectangular shape, butthis is only an example of the present invention, and it is not limitedthereto. In addition, the windows 301-305 go through the firstmagnetic-core frame 310, the second magnetic-core frames 320 a-320 c,and the third magnetic-core frame 330, respectively, from the side shownin the figure to another side, so that the coil windings La1-La3,Lb1-Lb3 can wind around the magnetic-core frames 310, 320 a-320 c, 330through the windows 301-305, respectively.

In this embodiment, the first magnetic-core frame 310 is composed of afirst side pillar 311 and a second side pillar 312 opposite to eachother, and a third side pillar 313 and a fourth side pillar 314 oppositeto each other. Each of the second magnetic-core frames 320 a-320 c iscomposed of corresponding first side pillars 321 a-321 c and second sidepillars 322 a-322 c opposite to each other, and third side pillars 323a-323 c and fourth side pillars 324 a-324 c opposite to each other,respectively. The second magnetic-core frames 320 a-320 c are allarranged on a first side of the first side pillar 311 of the firstmagnetic-core frame 310, and arranged in parallel with the axis of thefirst side pillar 311 of the first magnetic-core frame 310, so that thefirst side pillars 321 a-321 c of the second magnetic-core frames 320a-320 c are adjacent to the first side pillar 311 of the firstmagnetic-core frame 310, respectively. The third magnetic-core frame 330is composed of a first side pillar 331 and a second side pillar 332opposite to each other, and a third side pillar 333 and a fourth sidepillar 334 opposite to each other. The third magnetic-core frame 330 isarranged on a second side of each of the second side pillars 322 a-322 cof the second magnetic-core frames 320 a-320 c, so that the first sidepillar 331 of the third magnetic-core frame 330 is adjacent to thesecond side pillars 322 a-322 c of the second magnetic-core frames 320a-320 c, respectively. In addition, the first magnetic-core frame 310and each of the second magnetic-core frames 320 a-320 c are respectivelyspaced apart from each other by a distance S1 to form air gaps, and thethird magnetic-core frame 330 and each of the second magnetic-coreframes 320 a-320 c are respectively spaced apart from each other by adistance S2 to form air gaps. In the present embodiment, the distancesS1 and S2 are the same, but this is only an example of the presentinvention, and it is not limited thereto.

Each of the first coil windings La1-La3 winds around the first sidepillar 311 of the first magnetic-core frame 310 and the correspondingsecond side pillars 321 a-321 c of the second magnetic-core frames 320a-320 c, respectively. For example, as shown in the figure, the firstcoil winding La1 winds around the first side pillar 311 of the firstmagnetic-core frame 310 and the first side pillar 321 a of the secondmagnetic-core frame 320 a through the window 301 and the window 302. Thefirst coil winding La2 winds around the first side pillar 311 of thefirst magnetic-core frame 310 and the first side pillar 321 b of thesecond magnetic-core frame 320 b through the window 301 and the window303. The first coil winding La3 winds around the first side pillar 311of the first magnetic-core frame 310 and the first side pillar 321 c ofthe second magnetic-core frame 320 c through the window 301 and thewindow 304. The winding directions of the first coil windings La1-La3are the same.

In addition, each of the second coil windings Lb1-Lb3 winds around thecorresponding second side pillars 322 a to 322 c of the secondmagnetic-core frames 320 a-320 c and the first side pillar 331 of thethird magnetic-core frame 330. For example, as shown in the figure, thesecond coil winding Lb1 winds around the first side pillar 331 of thethird magnetic-core frame 330 and the second side pillar 322 a of thesecond magnetic-core frame 320 a through the window 305 and the window302. The second coil winding Lb2 winds around the first side pillar 331of the third magnetic-core frame 330 and the second side pillar 322 b ofthe second magnetic-core frame 320 b through the window 305 and thewindow 303. The second coil winding Lb3 winds around the first sidepillar 331 of the third magnetic-core frame 330 and the second sidepillar 322 c of the second magnetic-core frame 320 c through the window305 and the window 304. The winding directions of the second coilwindings Lb1-Lb3 are the same, but are opposite to the windingdirections of the first coil windings La1-La3.

In this embodiment, the first magnetic-core frame 310, the secondmagnetic-core frames 320 a-320 c, and the third magnetic-core frame 330can be made of the same material. For example, the first magnetic-coreframe 310, the second magnetic-core frames 320 a-320 c, and the thirdmagnetic-core frame 330 can be made of the silicon steel sheet or theiron powder core. In another embodiment, in order to provide betterhigh-frequency characteristics, the first magnetic-core frame 310 andthe third magnetic-core frame 330 which having the common-mode effectcan be made of manganese zinc or a ferrite material to enhance thesuppression of the EMI at high frequencies, and each of the secondmagnetic-core frames 320 a-320 c is made of a silicon steel sheet or aniron powder core to lower the cost of production.

In addition, since the three-phase integrated reactor described in thesecond embodiment provides two sets of inductors, in one example, thethree-phase integrated reactor can be connected in series with a set ofcapacitors and a LCL circuit. Referring to FIG. 4, wherein FIG. 4 is aschematic diagram of a circuit architecture having the LCL circuit. TheLCL circuit 420 which in combination with a three-phase integratedreactor and a set of capacitors can be connected in series between athree-phase grid 410 and an input terminal of a device 430. The device430 can be an active front end (AFE) circuit, a REG circuit, an APFcircuit, or an SVG circuit. Compared with the common LCL circuit whichonly has the effect of common-mode, the architecture of the LCL circuitrecited in the second embodiment of the present invention has both theeffect of common-mode and differential-mode at the same time, which cansmooth the suddenly-increased current and raise the amount ofhigh-frequency noise suppression.

FIGS. 5A and 5B are schematic side views of an integrated three-phasecurrent sensor common-mode choke with different air gaps in accordancewith a third embodiment of the present invention. In general, the outputterminal of a general VFD system has a set of Hall sensor modules fordetecting variation of the current. The integrated three-phase currentsensor common-mode choke described below achieves the effect ofsuppressing the common-mode and also provides the function of currentdetection. The integrated three-phase current sensor common-mode chokeincludes a magnetic-core frame 510, three C-type magnetic cores 520a-520 c, and three coil windings La1-La3. The first magnetic-core frame510 provides the common-mode effect while the C-type magnetic cores 520a-520 c provide the differential-mode effect and current detectionfunctions (respectively numbered as CM and DM with arrow index). Themagnetic-core frame 510 can be a close-looped magnetic circuit with anysuitable shape, and it includes a window 501. It should be noted thatalthough the magnetic-core frame 510 shown in FIG. 5A is having arectangular shape, this is only an example of the present invention andit is not limited thereto. Each of the C-type magnetic cores 520 a-520 cis presented as a C-shaped element and respectively includes a relativelarger window 502-504 therein, and a relative smaller gap 550 a-550 c onthe opposite sides of first side pillars 521 a-521 c thereof. Thewindows 501-504 pass through the magnetic-core frame 510 and the C-typemagnetic cores 520 a-520 c, respectively, from one side shown in FIG. 5Ato the other side, so that the coil windings La1-La3 can wind around themagnetic-core frame 510 and the C-type magnetic cores 520 a-520 cthrough the windows 501-504, respectively.

In this embodiment, the magnetic-core frame 510 includes a first sidepillar 511 and a second side pillar 512 opposite to each other, and athird side pillar 513 and a fourth side pillar 514 opposite to eachother. The C-type magnetic cores 520 a-520 c are all arranged on a sidecorresponding to the first side pillar 511 of the magnetic-core frame510, and are arranged in parallel with the axis of the first side pillar511 of the magnetic-core frame 510, so that the first side pillars 521a-521 c of the C-type magnetic cores 520 a-520 c are adjacent to thefirst side pillar 511 of the magnetic-core frame 510, respectively. Themagnetic-core frame 510 and each of the C-type magnetic cores 520 a-520c are spaced apart from each other by a distance S to form air gaps. Inthe present embodiment, the distances S are the same, but these are onlyexamples of the present invention and it is not limited thereto.Furthermore, as shown in FIG. 5B, the magnetic-core frame 510 and theC-type magnetic cores 520 a-520 c can be integrated into a one-piecestructure by processes or other means, which means that a magnetic-coreframe and C-type magnetic cores can be formed into a structure withoutair gaps.

In addition, Hall sensors 570 a-570 c are provided in each of thecorresponding smaller gaps 550 a-550 c of the C-type magnetic cores 520a-520 c respectively for sensing the magnetic field variations of thecorresponding C-type magnetic cores 520 a-520 c. each of the coilwindings La1-La3 respectively winds around the first side pillar 511 ofthe magnetic-core frame 510 and the corresponding first side pillars 521a-521 c of the C-type magnetic cores 520 a-520 c. For example, as shownin the figure, the coil winding La1 winds around the first side pillar511 of the magnetic-core frame 510 and the first side pillar 521 a ofthe C-type magnetic core 520 a through the window 501 and the window502. The coil winding La2 winds around the first side pillar 511 of themagnetic-core frame 510 and the first side pillar 521 b of the C-typemagnetic core 520 b through the window 501 and the window 503. The coilwinding La3 winds around the first side pillar 511 of the magnetic-coreframe 510 and the first side pillar 521 c of the C-type magnetic core520 c through the window 501 and the window 504. The winding directionsof the coil windings La1-La3 are the same.

The integrated three-phase current sensor common-mode choke described inthe third embodiment can be adapted and connected in series between theoutput terminal of the VFD 202 and the motor 203 (such as the portion“B” shown in right part of FIG. 2) for detecting the current that drivesthe motor 203, and determining the switching period of the switch. Theintegrated three-phase current sensor common-mode choke system recitedin this embodiment can be also adapted to filter noise between the VFD202 and the motor 203.

FIGS. 6A and 6B are schematic side views of a two-phase integratedreactor having different air gaps in accordance with a fourth embodimentof the present invention. The two-phase integrated reactor includes amagnetic-core frame 610, a first C-type magnetic core 620, a secondC-type magnetic core 630, a first coil winding La, and a second coilwinding Lb. The magnetic-core frame 610 provides the common-mode effect,and the first C-type magnetic core 620 and the second C-type magneticcore 630 provide the differential-mode effect (respectively numbered asCM and DM with arrow index). The magnetic-core frame 610 can be aclose-looped magnetic circuit with any suitable shape, and it includes awindow 601. It should be noted that although the magnetic-core frame 610shown in FIG. 6A is having a rectangular shape, but this is only oneexample of the present invention and it is not limited thereto. Each ofthe first C-type magnetic core 620 and the second C-type magnetic core630 is a C-shaped element. The first C-type magnetic core 620 includes arelative larger window 602 and a relative smaller gap 625 located at theside corresponding to the first side pillar 621 of itself. The secondC-type magnetic core 630 includes a relative larger window 603 and arelative smaller gap 635 located at the side corresponding to the firstside pillar 631 of itself. The windows 601-603 respectively passesthrough the magnetic-core frame 610, the first C-type magnetic core 620,and the second C-type magnetic core 630 from a side shown in FIG. 6A toanother side, so that the coil windings La, Lb can wind around themagnetic-core frame 610, the first C-type magnetic core 620 and thesecond C-type magnetic core 630 through the windows 601-603,respectively.

In this embodiment, the magnetic-core frame 610 includes a first sidepillar 611 and a second side pillar 612 opposite to each other, and athird side pillar 613 and a fourth side pillar 614 opposite to eachother. The first C-type magnetic core 620 is disposed on a sidecorresponding to the first side pillar 611 of the magnetic-core frame610, so that the first side pillar 621 of the first C-type magnetic core620 is adjacent to the first side pillar 611 of the magnetic-core frame610. The gap 625 of the first C-type magnetic core 620 is located at aside that is far away from the first side pillar 611 of themagnetic-core frame 610. The second C-type magnetic core 630 is disposedon a side corresponding to the second side pillar 612 of themagnetic-core frame 610, so that the first side pillar 631 of the secondC-type magnetic core 630 is adjacent to the second side pillar 612 ofthe magnetic-core frame 610. The gap 635 of the second C-type magneticcore 630 is located at a side that is far away from the second sidepillar 612 of the magnetic-core frame 610. The magnetic-core frame 610,the first C-type magnetic core 620, and the second C-type magnetic core630 are spaced apart from each other by a distance S1 and S2 to form airgaps, respectively. In the present embodiment, the distances S1 and S2are the same, but this is only an example of the present invention andit is not limited thereto.

The coil winding La connects to one of the P and N input terminals, andwinds around the first side pillar 611 of the magnetic-core frame 610and the first side pillar 621 of the first C-type magnetic core 620through the window 601 and the window 602, respectively. The coilwinding Lb connects to the other of the P and N input terminals, andwinds around the second side pillar 612 of the magnetic-core frame 610and the first side pillar 631 of the second C-type magnetic core 630through the window 601 and the window 603, respectively. The windingdirections of the coil windings La and Lb are the same.

In this embodiment, the magnetic-core frame 610, the first C-typemagnetic core 620, and the second C-type magnetic core 630 can be madeof the same material, for example, they can be made of silicon steelsheets or iron powder cores. In cases where the magnetic-core frame 610,the first C-type magnetic core 620, and the second C-type magnetic core630 are made of the same material, it can be shown as the architectureshown in FIG. 6B. In this embodiment, there is a special case that noair gap between the magnetic-core frame 610 and the first C-typemagnetic core 620 or between the magnetic-core frame 610 and the secondC-type magnetic core 630. That is, the magnetic-core frame 610, thefirst C-type magnetic core 620, and the second C-type magnetic core 630can be integrated into a one-piece structure, but it is not limitedthereto. In another embodiment, in order to provide betterhigh-frequency characteristics, the magnetic-core frame 610 having thecommon-mode effect can be made of manganese zinc or ferrite to increaseEMI suppression at high frequencies. The first C-type magnetic core 620and the second C-type magnetic core 630 can be made of a silicon steelsheet or iron powder core to lower the cost of production.

In the fourth embodiment, the two-phase integrated reactor can beadapted as a reactor for the DC link PN input terminal in an inverter.FIG. 7 is a schematic diagram of the structure of a general VFD system.As shown in FIG. 7, the two-phase integrated reactor 730 described inthe fourth embodiment is connected in series between a rectifier 720 andan inverter 740, and the system may further include a three-phase grid710 located at the front end and a motor 750 at the rear endrespectively. In the conventional technique, only one reactor isprovided at the PN input terminal, so that the inductance of thecommon-mode is low and therefore has less effective for the common-mode.However, the two-phase integrated reactor of the present inventionsignificantly increases the inductance of the common-mode at the highfrequency. In addition, the two-phase integrated reactor can also beapplied to the REG circuit to block the circular current that flows backto the three-phase grid.

According to an embodiment of the present invention, the PN currentmight be unbalanced due to the erroneous operation during thetransformer is operated, which might cause a ground fault in the machineor system. Therefore, in order to detect the abnormal situation of PNcurrent as soon as possible, a coil winding can be added to themagnetic-core frame 610 of the two-phase integrated reactor described inthe fourth embodiment to detect the current at the PN terminal. Forexample, as shown in FIG. 8, FIG. 8 is a schematic side view of atwo-phase integrated reactor having a ground fault detection function inaccordance with a fifth embodiment of the present invention. Thestructure of the magnetic-core frame 810, the first C-type magnetic core820, the second C-type magnetic core 830, the first coil winding La, andthe second coil winding Lb shown in FIG. 8 are substantially the same asthe two-phase integrated reactor shown in FIG. 6A, thus it is notdescribed herein to simplify the description. An additional coil winding850 is added at the third side pillar 813 of the magnetic-core frame 810to sense the current at the PN terminal. The coil winding 850 is furtherconnected to a controller (not shown), but it is not applied with thecurrent, and is only used for sensing the current. The sensed currentsignal will be transmitted to the controller to execute the preventiveprocess.

FIG. 9A is a schematic side view of an enhanced differential-mode andcommon-mode reactor in accordance with a sixth embodiment of the presentinvention. FIG. 9B is a schematic side view of a magnetic-core frame ofthe enhanced differential-mode and common-mode reactor in accordancewith the sixth embodiment of the present invention. FIG. 9C is aschematic side view of a core module of the enhanced differential-modeand common-mode reactor in accordance with the sixth embodiment of thepresent invention. As shown in the figure, the enhanceddifferential-mode common-mode reactor includes a magnetic-core frame910, a core module, a first coil winding La, and a second coil windingLb. The magnetic-core frame 910 and the core modules are stackedtogether vertically, which means that the magnetic-core frame 910overlaps the core module in a projection direction. The magnetic-coreframe 910 is used to provide the common-mode effect (numbered as CM witharrow index shown in FIG. 9B) and the core module provides thedifferential-mode effect (numbered as DM with arrow index shown in FIG.9C), and the differential-mode current shown in the dotted line is drawnback from the center pillar of the core module to the side pillar of thecore module. The structure of the core module will be described indetail later. As shown in FIG. 9B, the magnetic-core frame 910 can be aclose-looped magnetic circuit with any suitable shape, and it includes awindow 901. The magnetic-core frame 910 includes a first side pillar 911and a second side pillar 912 opposite to each other, and a third sidepillar 913 and a fourth side pillar 914 opposite to each other. Althoughthe magnetic-core frame 910 shown in FIG. 9B is having a rectangularshape, but this is only an example of the present invention and it isnot limited thereto.

As shown in FIG. 9C, the core module includes an E-type magnetic core920 and an I-type magnetic core 930. The E-type magnetic core 920includes a first side pillar 921, a second side pillar 922, a centerpillar 923, and a third side pillar 924. The first side pillar 921, thesecond side pillar 922, and the center pillar 923 are substantiallyparallel to each other, and the first side pillar 921 and the secondside pillar 922 are located at opposite sides of the center pillar 923,respectively. In addition, the first side pillar 921, the second sidepillar 922, and the center pillar 923 are all perpendicular to the thirdside pillar 924. The I-type magnetic core 930 is provided on a sidecorresponding to the third side pillar 924 of the E-type magnetic core920, and the first side pillar 921 and the second side pillar 922 of theE-type magnetic core 920 and the I-type magnetic core 930 are spacedapart from each other by a distance S1 to form air gaps, respectively,in order to facilitate the adjustment of the magnetic properties. Indetail, the distances S1 between the first side pillar 921 or the secondside pillar 922 of the E-type magnetic core 920 and the I-type magneticcore 930 are the same, and the distances S1 can be adjusted based on theconfiguration of the I-type magnetic core 930 and the E-type magneticcore 920, that is, the air gaps between the I-type magnetic core 930 andthe E-type magnetic core 920 can be adjusted. In the present embodiment,the center pillar 923 of the E-type magnetic core 920 is shorter thanboth the first side pillar 921 and the second side pillar 922 of theE-type magnetic core 920 (as shown in FIG. 9C, the distance S1 issmaller than the distance S2), but this is only an example of thepresent invention and it is not limited thereto.

Referring to FIGS. 9A, 9B and 9C, the coil winding La winds around thefirst side pillar 911 of the magnetic-core frame 910 and the first sidepillar 921 of the E-type magnetic core 920 through the window 901 of themagnetic-core frame 910. The coil winding Lb winds around the secondside pillar 912 of the magnetic-core frame 910 and the second sidepillar 922 of the E-type magnetic core 920 through the window 901 of themagnetic-core frame 910. The winding directions of the coil windings Laand Lb are the same.

In this embodiment, the magnetic-core frame 910 and the core module canbe made of the same material, for example, they can be made of thesilicon steel sheets or the iron powder cores. In another embodiment, inorder to provide a better common-mode effect, the magnetic-core frame910 can also be made of the manganese zinc or the ferrite, and the coremodule is made of the silicon steel sheets or the iron powder core toenhance the high-frequency common-mode effect and to lower theproduction costs.

As described above, according to the various integrated magneticelements of embodiments of the present invention, it is possible toachieve the effects of suppressing the common-mode noise and thedifferential-mode noise at the same time without placing an extracapacitor for increasing the EMI suppression effect in the VFD system,which can avoid the sides effects that the capacitor might generate alarge leakage current or high voltage noise will be entered into thecapacitor. In addition, the design of the system design can besimplified to reduce the size and the costs of the system or the device.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure disclosedwithout departing from the scope or spirit of the invention. In view ofthe foregoing, it is intended that the present invention coversmodifications and variations of this invention, provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. An integrated magnetic element, comprising: afirst magnetic-core frame, having a first side pillar and a second sidepillar opposite to the first side pillar; three second magnetic-coreframes, arranged on a side corresponding to the first side pillar of thefirst magnetic-core frame, and arranged in parallel with an axis of thefirst side pillar of the first magnetic-core frame, wherein each of thesecond magnetic-core frames has a first side pillar adjacent to thefirst side pillar of the first magnetic-core frame, and a second sidepillar opposite to the first side pillar of itself; and three coilwindings, connected to a three-phase grid, and winding around the firstside pillar of the first magnetic-core frame and the corresponding firstside pillar of the second magnetic-core frame respectively.
 2. Theintegrated magnetic element as claimed in claim 1, wherein theintegrated magnetic element is connected in series between thethree-phase grid and a VFD system.
 3. The integrated magnetic element asclaimed in claim 1, wherein each of the three coil windings has the samewinding direction.
 4. The integrated magnetic element as claimed inclaim 1, wherein the first magnetic-core frame and the secondmagnetic-core frame are made of the same material.
 5. The integratedmagnetic element as claimed in claim 1, wherein the first magnetic-coreframe is made of a different material than the second magnetic-coreframe.
 6. An integrated magnetic element, comprising: a firstmagnetic-core frame, having a first side pillar and a second side pillaropposite to the first side pillar; three second magnetic cores, arrangedon a side of the first side pillar of the first magnetic-core frame, andarranged in parallel with the axis of the first side pillar of the firstmagnetic-core frame, wherein each of the second magnetic-core frames hasa first side pillar adjacent to the first side pillar of the firstmagnetic-core frame, and a second side pillar opposite to the first sidepillar of itself; a third magnetic-core frame, arranged on a side of thesecond side pillar of the three second magnetic-core frames, and havinga first side pillar adjacent to the second side pillar of the threesecond magnetic-core frames, and a second side pillar opposite to thefirst side pillar of itself; three first coil windings, connected to athree-phase grid, and respectively winding around the first side pillarof the first magnetic-core frame and the corresponding first side pillarof the second magnetic-core frame; and three second coil windings,respectively winding around the corresponding second side pillar of thesecond magnetic-core frame and the first side pillar of the thirdmagnetic-core frame.
 7. The integrated magnetic element as claimed inclaim 6, wherein all of the first coil windings have the same firstwinding direction, and all of the second coils have the same secondwinding direction, and wherein the first winding direction is differentfrom the second winding direction.
 8. The integrated magnetic element asclaimed in claim 6, wherein the first magnetic-core frame, the secondmagnetic-core frame, and the third magnetic-core frame are made of thesame material.
 9. The integrated magnetic element as claimed in claim 6,wherein the first magnetic-core frame or the third magnetic-core frameis made of a different material than the second magnetic-core frame. 10.The integrated magnetic element as claimed in claim 6, furthercomprising: a set of capacitors, respectively connected in seriesbetween the corresponding first coil winding and the correspondingsecond coil winding for forming an LCL filter.
 11. The integratedmagnetic element as claimed in claim 10, wherein the integrated magneticelement is connected in series between the three-phase grid and anactive front-end circuit, a REG circuit, an APF circuit, or an SVGcircuit.